一.基本概念
UIKit框架中，可以直接执行拷贝黏贴操作的有：UITextView、UITextField和UIWebView，其他控件需要实现相关方法。
关于UIPasteboard
·黏贴板是app内或者app之间，交换数据的标准机制
·有公开的也有私有的，公开的黏贴板为系统级别(system pasteboard)，私有的黏贴板为应用程序级别(app pasteboard)，系统级别的黏贴板可以分享数据给任意其他app，应用程序级别的黏贴板只能分享给应用本身或者有相同team ID的应用
·system pasteboard默认是持久化的，所谓持久化，就是设备重启或者app卸载依然有效，app pasteboard默认是非持久化的，可以通过persistent修改
@property(getter=isPersistent,nonatomic) BOOL persistent;一般使用名为UIPasteboardNameGeneral的system pasteboard，这货是个单例对象，是整个手机所有app共享的黏贴板
UIPasteboard *generalPasteboard = [UIPasteboard generalPasteboard];二.具体实现
以label为例，假设label轻触两下或者长按显示编辑菜单
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过程将会涉及
·UIPasteboard：提供黏贴板分享数据，从黏贴板读-写数据
·UIMenuController：展示编辑菜单，用来执行拷贝-黏贴操作
·UIResponder类的canPerformAction:withSender:方法，决定是否显示菜单某些命令，例如剪切
·UIResponderStandardEditActions非正式协议中声明了copy、cut、paste等方法，需要实现
注：展示编辑菜单之前，系统会发送canPerformAction:withSender:消息给第一响应者，所以控件需要成为第一响应者来接收消息，并且在这个方法中，根据上下文的环境评估命令是否可用，例如当黏贴板没有可处理的数据时，响应者应该返回NO，阻止黏贴命令
0.首先打开用户交互，这个不要忘记，添加手势
- (void)awakeFromNib {
[super awakeFromNib];
UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(showMenu:)];
longPress.minimumPressDuration = 0.5;
[self addGestureRecognizer:longPress];
}
- (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
if (touch.tapCount == 2) {
[self showMenu:nil];
}
}1.是否可以成为第一响应者，默认为NO
- (BOOL)canBecomeFirstResponder {
return YES;
}2.成为第一响应者
[self becomeFirstResponder];3.创建编辑菜单
//获得单例对象UIMenuController *menu = [UIMenuController sharedMenuController];//view是参照物，指向以view为参照物的rect[menu setTargetRect:self.bounds inView:self];//显示[menu setMenuVisible:YES animated:YES];4.实现canPerformAction:withSender:方法，参数action具体会有哪些方法，基本都在UIResponderStandardEditActions声明了
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender {
NSLog(@"%@",NSStringFromSelector(action));
NSLog(@"%@",sender);
if (action == @selector(copy:) && self.text) { //显示条件是文本不为空
return YES;
} else if (action ==@selector(cut:) && self.text) { //显示条件是文本不为空
return YES;
} else if (action == @selector(paste:) && [UIPasteboard generalPasteboard].string) { //显示条件是黏贴板不为空
return YES;
} else {
return NO;
}
}5.实现copy、cut、paste等方法
//实现剪切
- (void)cut:(id)sender {
[self copy:sender];
self.text = nil;
}
//实现拷贝
- (void)copy:(id)sender {
[UIPasteboard generalPasteboard].string = self.text;
}
//实现黏贴
- (void)paste:(id)sender {
UIPasteboard *generalPasteboard = [UIPasteboard generalPasteboard]; NSMutableArray *types = [[NSMutableArray alloc] init];
[types addObjectsFromArray:UIPasteboardTypeListString];
if ([generalPasteboard containsPasteboardTypes:types]) {
self.text = generalPasteboard.string;
}
}6.如果想要添加自定义命令，可以创建UIMenuItem
//添加自定义菜单项
UIMenuItem *item = [[UIMenuItem alloc] initWithTitle:@"Change Color" action:@selector(changeColor:)];
menu.menuItems = @[item];再以imageView为例，展示图片拷贝黏贴操作
#import "CustomImageView.h"@implementation CustomImageView- (void)awakeFromNib {
[super awakeFromNib];
UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(showMenu:)];
longPress.minimumPressDuration = 0.5;
[self addGestureRecognizer:longPress];
}
- (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
if (touch.tapCount == 2) {
[self showMenu:nil];
}
}
/** * 4.响应者是否可以执行该方法 * * @param action 方法 * @param sender 请求对象 */
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender {
if (action == @selector(copy:) && self.image) {
return YES;
} else if (action == @selector(cut:) && self.image) {
return YES;
} else if (action == @selector(paste:) && [UIPasteboard generalPasteboard].image) {
return YES;
} else if (action == @selector(changeColor:)) {
return YES;
} else {
return NO;
}
}
/** * 1.是否可以成为第一响应者，默认为NO *
/- (BOOL)canBecomeFirstResponder {
return YES;
}
- (void)showMenu:(UILongPressGestureRecognizer *)longPress {
if (longPress.state == UIGestureRecognizerStateEnded || longPress == nil) { //2.成为第一响应者
[self becomeFirstResponder]; //添加自定义菜单项
UIMenuItem *item = [[UIMenuItem alloc] initWithTitle:@"Change Color" action:@selector(changeColor:)]; //3.创建编辑菜单
UIMenuController *menu = [UIMenuController sharedMenuController];
[menu setTargetRect:self.bounds inView:self];
menu.menuItems = @[item];
[menu setMenuVisible:YES animated:YES];
}
}
- (void)cut:(id)sender {
[self copy:sender];
self.image = nil; }
- (void)copy:(id)sender {
[UIPasteboard generalPasteboard].image = self.image;
}
- (void)paste:(id)sender {
UIPasteboard *generalPasteboard = [UIPasteboard generalPasteboard];
NSMutableArray *types = [[NSMutableArray alloc] init];
[types addObjectsFromArray:UIPasteboardTypeListImage];
if ([generalPasteboard containsPasteboardTypes:types]) {
self.image = generalPasteboard.image;
}
}
- (void)changeColor:(id)sender {
self.backgroundColor = [UIColor colorWithRed:arc4random_uniform(256)/255.0 green:arc4random_uniform(256)/255.0 blue:arc4random_uniform(256)/255.0 alpha:1.0];
}aaarticlea/png;base64,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" alt="" data-ratio="1.6079136690647482" data-src="http://mmbiz.qpic.cn/mmbiz/g4uoJOMA38LLFWhB4dvm9mtEdAwLxmoiaytJLSjtVbuSAKPeicp3CpAXZBLib0COTrgwZxl1iaMWIChoXBic9yk2kRQ/0?wx_fmt=png" data-type="png" data-w="" />
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屏幕快照 2016-04-28 下午9.30.34.png
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